US fugitive Edward Snowden has abandoned his request for political asylum in Russia after learning he would have to stop leaking intelligence reports, the Kremlin said Tuesday, as the American awaited asylum decisions from 20 other countries.

Snowden, who is holed up at Moscow's Sheremetyevo airport, has accused Washington of pressuring foreign leaders to refuse him refuge as he tries to evade justice for revealing a vast US spying programme that has strained ties with European allies.

"These are the old, bad tools of political aggression," Snowden said in a statement published Monday by the anti-secrecy WikiLeaks website.

"Their purpose is to frighten, not me, but those who would come after me."

WikiLeaks, which has been helping Snowden, said the 30-year-old had sent asylum requests to 21 countries.

Russia, Norway, Austria and Poland were among the first to confirm they had received the applications. Warsaw immediately rejected the request.

Snowden's latest major leak about US spying on EU countries has angered many European governments and threatens to derail preparations for talks on a huge free trade deal between Washington and Brussels.

Russian President Vladimir Putin on Monday said Snowden was welcome to stay as long as he stopped leaking US intelligence reports.

"If he (Snowden) wants to remain here there is one condition -- he should stop his work aimed at inflicting damage on our American partners no matter how strange this may sound coming from me," Putin told reporters.

But after learning of that condition, a Kremlin spokesman said Snowden withdrew his request.

"He abandoned his intention and his request to receive the chance of staying in Russia," Russian President Vladimir Putin's spokesman, Dmitry Peskov, told reporters.

Ecuador -- the first country to which Snowden applied for asylum -- had earlier voiced relief at the possibility of Russia taking in Snowden.

"My opinion is that the (asylum) request to the Russian government could definitely resolve Mr. Snowden's situation," President Rafael Correa told AFP in an interview.

That the Moscow option has reached a dead end could increase pressure on Ecuador, which has hesitated over the case in the face of possible economic sanctions from the United States.

Snowden had remained quiet and out of sight of reporters since arriving in the transit zone of Moscow Sheremetyevo Airport from Hong Kong on June 23.

He had planned to travel on to Cuba the following day but never got on the flight because he apparently lacked the proper boarding papers after his US travel passport was revoked.

Breaking his silence for the first time since then, Snowden said in the statement published by WikiLeaks: "Without any judicial order, the administration now seeks to stop me exercising a basic right. A right that belongs to everybody. The right to seek asylum."

Snowden also called Ecuador's treatment of those who stand up to US interests "an example to the world".

"There are few world leaders who would risk standing for the human rights of an individual against the most powerful government on earth, and the bravery of Ecuador and its people is an example to the world," Snowden wrote in a letter to Correa that was obtained by Britain's Press Association.

Putin himself said on Monday that Snowden sees himself as a political crusader for moral justice akin to the 1975 Nobel Peace Prize winning Soviet-era dissident Andrei Sakharov.

The Kremlin chief suggested that this meant that Snowden was unlikely to meet Russia's condition of ending his leaks against the United States.

"Because he feels like a rights activist and defender of human rights all indications are that he is not going to stop this work. So he has to choose a country of residence for himself and move there."

Putin's spokesman Peskov said that Snowden had personally informed Russian officials that he was no longer interested in staying in Moscow.

But Peskov also emphasised that Russia had no intention of handing the fugitive over to the United States.

"The handover of Snowden to a country like the United States that applies the death penalty is impossible," Peskov told reporters.

US President Barack Obama for his part confirmed that there were high-level consultations between Moscow and Washington over Snowden's fate.

"We have gone through regular, law enforcement channels in enforcing the extradition request that we have made with respect to Mr Snowden," Obama said while on his African visit Monday.

"Mr Snowden, we understand, has travelled there without a valid passport, without legal papers. We are hopeful that the Russian government makes decisions based on the normal procedures regarding international travel."